1. Field of the Invention
The present invention is generally related to medical ultrasound, and more particularly to a non-invasive screening method and apparatus for visualizing coronary artery obstruction which solves artery curvature problems by projecting the three-dimensional volume onto a two-dimensional screen, highlighting the arteries and veins in contrast to other tissue and the heart chambers by using nonlinear techniques, storing many processed 2D slices into a 3D volume, and projecting the volume with varying view angles controlled by a pointing device.
2. Discussion of Related Art including information disclosed under 37 CFR §§1.97, 1.98
In his well-respected textbook, Echocardiography, Harvey Feigenbaum, M.D., describes analysis techniques for many cardiac conditions. Most of these are used in routine clinical practice. An exception is the visualization of the coronary arteries (CAs) and assessment of their condition. Considering the seriousness of coronary artery disease, it is obvious that a non-invasive screening technique to assess obstruction in these arteries would be of great importance.
At pages 482-490 of Echocardiography, 5th Edition, Feigenbaum shows 2D views of the coronary arteries. These studies prove that clinical ultrasound machines circa 1993 already had sufficient resolution to image the larger parts of these arteries. However, as Feigenbaum states, the curved nature of the arteries usually does not permit them to be seen for any length in an individual frame. In addition, it takes great skill and knowledge to recognize the arteries when they do come into view. For these reasons, clinical ultrasound is rarely used to visualize the CAs.
Because of the curved nature of the CAs, it would be advantageous and desirable to visualize them in three dimensions. The current patent teaches the steps required to achieve this goal.
Several U.S. Patents and/or patent applications teach or show methods of imaging coronary arteries using ultrasound or other medical imaging techniques. Notable among them are U.S. Pat. Appln. No. 2006/0079782, by Beach et al., which shows an ultrasonic technique for visualizing coronary arteries using a 2-D scan and a 3-D display.
U.S. Pat. Appln. No. 2006/0079759, by Vaillant et al., discloses a method and apparatus for registering 3-D models of the heart using ultrasound.
U.S. Pat. Appln. No. 2005/0281447, by Moreau-Gobard et al., teaches a method of producing a 3-D image of the coronary artery system using ultrasound.
U.S. Pat. Appln. No. 2005/0004449, by Mitschke et al., teaches the use of ultrasound to acquire preoperative 3-D images for marker-less navigation of a medical instrument.
U.S. Pat. Appln. No. 20020087071, by Schmitz et al., teaches a process for graphic visualization and diagnosis of thrombi as well as the use of particle suspensions for the production of contrast media for the visualization of thrombi (circumscribed blood solidification that forms in arteries or veins by intravascular clotting) through the use of nuclear spin tomography. This method produces 3-D images from a 2-D source.
U.S. Pat. No. 6,148,095, to Prause et al., shows a method of three-dimensional reconstruction of coronary arteries by fusing data between biplane angiography and IVUS frames of a pullback sequence. The 3D course of the tortuous vessel is first determined from the angiograms and then combined with the 2D representations regarding the 3D course (e.g., segmented IVUS frames of a pullback sequence) using a data fusion apparatus and method: The determination of the 3D pullback path is represented by the external energy of the tortuous vessel and the internal energy of a line object such as a catheter.
U.S. Pat. Appln. No. 2005/0288588, by Weber et al., discloses a method and apparatus for electronic volume data acquisition using ultrasound generates image data in a coherent aperture combining beamforming (CAC-BF) scanning and imaging process.
U.S. Pat. No. 6,166,853, to Sapia et al., teaches use of an adaptive structure of a Wiener filter to deconvolve three-dimensional wide-field microscope images for the purposes of improving spatial resolution and removing out-of-focus light. The filter is a three-dimensional kernel representing a finite-impulse-response (FIR) structure requiring on the order of one thousand (1,000) taps or more to achieve an acceptable mean-square-error. Converging to a solution is done in the spatial-domain. Alternatively, a three-dimensional kernel representing an infinite-impulse-response (IIR) structure may be employed, as an IIR structure typically requires fewer taps to achieve the same or better performance, resulting in higher resolution images with less noise and faster computations.
The foregoing patents reflect the current state of the art of which the present inventor is aware. Reference to, and discussion of, these patents is intended to aid in discharging Applicant's acknowledged duty of candor in disclosing information that may be relevant to the examination of claims to the present invention. However, it is respectfully submitted that none of the above-indicated patents disclose, teach, suggest, show, or otherwise render obvious, either singly or when considered in combination, the invention described and claimed herein.